公开(公告)号：US20250004214A1

公开(公告)日：2025-01-02

申请号：US18707816

申请日：2022-11-10

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Takahito KIRIHARA ,  Satoshi Narikawa ,  Katsuhisa TAGUCHI ,  Ayako IWAKI ,  Kazuhide Nakajima ,  Takashi Matsui ,  Chisato Fukai ,  Yuto SAGAE ,  Tomohiro TANIGUCHI ,  Hiroyuki IIDA

IPC: G02B6/42 ,  A61L2/10 ,  A61L2/24 ,  A61L2/26

Abstract: An object of the present invention is to provide an optical transmission system capable of reducing system costs and reducing waste of output power of a light source. The optical transmission system according to the present invention includes an ultraviolet light source part 11a having a light emitting diode (LED) that outputs ultraviolet light, an optical transmission line 26 that propagates the ultraviolet light through a plurality of cores of a multi-core optical fiber or a plurality of cores of a bundle optical fiber obtained by bundling a plurality of single-core optical fibers, and an optical system 11c that narrows down a spot shape of the ultraviolet light output from the LED to a size including all of the plurality of cores in an optical axis direction, and causes the ultraviolet light to enter the plurality of cores.

公开(公告)号：US20240102886A1

公开(公告)日：2024-03-28

申请号：US18039600

申请日：2020-12-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Nobutomo HANZAWA ,  Takashi MATSUI ,  Yuto SAGAE ,  Kazuhide NAKAJIMA

IPC: G01M11/00 ,  C03C13/04

CPC classification number: G01M11/33 ,  C03C13/04 ,  C03C2213/00

Abstract: An object of the present invention is to provide an evaluation method and an evaluation device for easily determining whether or not a structural parameter of a multi-core fiber satisfies a desired connection loss value (a specification). The evaluation method according to the present invention includes a step of measuring center coordinates of each core with the center coordinates when a clad is approximated by a circle as an origin in an observed cross-sectional structure of the multi-core fiber to be objected, obtaining a length of a line segment connecting the origin and the center of each core and an angle formed by two line segments connecting the origin and two adjacent cores, and judging whether or not a desired connection loss characteristic is satisfied on the basis of whether or not the values satisfy a predetermined determination formula.

公开(公告)号：US20240007189A1

公开(公告)日：2024-01-04

申请号：US18021991

申请日：2020-08-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yuto SAGAE ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Taiji SAKAMOTO ,  Ryota IMADA

IPC: H04B10/291 ,  H04B10/25

CPC classification number: H04B10/2916 ,  H04B10/25 ,  G02B6/02042

Abstract: An object of the present invention is to provide an optical transmission system capable of satisfying XT required by a modulation system even if there is an inter-core loss difference in an MCF.
An optical transmission system of the present invention includes a multi-core optical fiber having a plurality of core regions and having different losses between at least two cores, a forward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in the same direction as signal light, and a backward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in a direction opposite to the signal light, wherein an intensity ratio of the forward excitation light to the backward excitation light is controlled (a ratio of power of excitation light is set to a predetermined value) such that crosstalk (XT) fluctuation between cores is reduced.

公开(公告)号：US20230390436A1

公开(公告)日：2023-12-07

申请号：US18032514

申请日：2020-10-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomohiro TANIGUCHI ,  Ayako IWAKI ,  Kazuhide NAKAJIMA ,  Nobutomo HANZAWA ,  Takashi MATSUI ,  Yuto SAGAE ,  Chisato FUKAI

IPC: A61L2/10

CPC classification number: A61L2/10 ,  A61L2202/11

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method which are not limited in an ultraviolet light irradiation region and can be introduced economically. The present ultraviolet light irradiation system is a system configured to connect a single ultraviolet light source part and an irradiation part installed in the vicinity of an object place to be sterilized or the like by the optical cable formed by bundling a plurality of optical fibers (the single-core or the multi-core) or the multi-core optical fiber. Since the optical fiber is very thin and does not require power supply for transmitting the ultraviolet rays, even in a fine place where a person or a robot cannot enter, the ultraviolet light can be irradiated by laying the optical fiber or the optical cable.

公开(公告)号：US20230280525A1

公开(公告)日：2023-09-07

申请号：US18024074

申请日：2020-09-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Taiji SAKAMOTO ,  Yuto SAGAE

IPC: G02B6/028 ,  G02B6/02

CPC classification number: G02B6/0288 ,  G02B6/02042

Abstract: The present disclosure relates to a multi-core optical fiber including:
M (where M is a positive integer of 1 or larger) group(s) each consisting of N (where N is a positive integer of 2 or larger) core regions linearly arranged in a cross section; a cladding region that surrounds the plurality of core regions and has a refractive index lower than any of the plurality of core regions; and a coating region that surrounds the cladding region, wherein the plurality of core regions are arranged in line symmetry with respect to both imaginary lines orthogonal to each other at a center of the cladding region, a diameter of the cladding region is 180 μm or less, and a diameter of the coating region is 235 μm or more and 265 μm or less.

公开(公告)号：US20230163554A1

公开(公告)日：2023-05-25

申请号：US17913097

申请日：2020-03-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shinichi AOZASA ,  Yoko YAMASHITA ,  Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Taiji SAKAMOTO ,  Nobutomo HANZAWA ,  Noriyuki ARAKI ,  Ryota IMADA ,  Yuto SAGAE

IPC: H01S3/067 ,  G02B6/32 ,  G02B3/08

CPC classification number: H01S3/06754 ,  G02B3/08 ,  G02B6/32 ,  H01S3/1608

Abstract: An object of the present disclosure is to implement a clad-excitation rare-earth-added optical fiber amplifier with a high light-to-light conversion efficiency. The present disclosure is an optical fiber amplifier having, in a longitudinal direction of a rare-earth-added optical fiber, a light collection structure that collets an excitation light, which propagates through a clad portion, into a core portion.

公开(公告)号：US20220294536A1

公开(公告)日：2022-09-15

申请号：US17634193

申请日：2019-08-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yuto SAGAE ,  Takashi MATSUI ,  Taiji SAKAMOTO ,  Kazuhide NAKAJIMA

IPC: H04B10/61

Abstract: An objective of the present invention is to provide an optical communication system and an optical communication method that can reduce even a delay generated in processing of obtaining a transfer function for correcting distortion in digital coherent transmission. In the optical communication system according to the present invention, pilot data for estimating a transfer function for a transmission channel is transmitted through a transmission channel with a short transmission delay time, a transfer function of the transmission channel is estimated before receiving transmission data, and the transfer function is applied to other transmission channels.

公开(公告)号：US20250093575A1

公开(公告)日：2025-03-20

申请号：US18294124

申请日：2021-08-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takashi MATSUI ,  Kazuhide NAKAJIMA ,  Nobutomo HANZAWA ,  Yuto SAGAE

IPC: G02B6/02

Abstract: An object of the present disclosure is to provide an optical fiber having a simple structure, as well as attaining removal of loss components generated in an electric field part oozing out to a core-clad interface or a clad region and reduction in scattering loss generated from an interface with the clad region.
The present disclosure relates to an optical fiber including a core for propagating light, a cladding disposed around the core, an air layer between the core and the cladding, and two or more bridges for supporting the core in the air layer.

公开(公告)号：US20240375093A1

公开(公告)日：2024-11-14

申请号：US18690903

申请日：2021-09-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Asuka MIYAKE ,  Hitoshi SESHIMO ,  Ryuji YAMAMOTO ,  Tomohiro TANIGUCHI ,  Ayako IWAKI ,  Satoshi NARIKAWA ,  Takahito KIRIHARA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Yuto SAGAE ,  Chisato FUKAI ,  Nobutomo HANZAWA

IPC: B01J35/39 ,  A61L2/10 ,  B01J35/54

Abstract: An object of the present invention is to provide a photocatalytic sheet configured to perform disinfection independent of the state of external light.
A photocatalytic sheet 50 according to the present invention includes a sheet 10 having a photocatalytic layer 17 on one surface, and an optical fiber 20 embedded in the sheet 10 and configured to supply ultraviolet light UV from inside of the sheet 10 to the photocatalytic layer 17. In the photocatalytic sheet, ultraviolet light is supplied from the optical fiber disposed in the sheet to the photocatalytic layer coated on the surface of the sheet (ultraviolet light is supplied from the back of the photocatalytic layer). This configuration allows for disinfection independent of the state of external light.

公开(公告)号：US20240277886A1

公开(公告)日：2024-08-22

申请号：US18693133

申请日：2021-09-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Asuka MIYAKE ,  Hitoshi SESHIMO ,  Ryuji YAMAMOTO ,  Tomohiro TANIGUCHI ,  Ayako IWAKI ,  Satoshi NARIKAWA ,  Takahito KIRIHARA ,  Kazuhide NAKAJIMA ,  Takashi MATSUI ,  Yuto SAGAE ,  Chisato FUKAI ,  Nobutomo HANZAWA

IPC: A61L9/20 ,  F24F8/22

CPC classification number: A61L9/20 ,  F24F8/22 ,  A61L2209/12 ,  A61L2209/16

Abstract: An object of the present invention is to provide an air conditioner unit that allows for greater flexibility in designing the shape of the unit and is capable of reducing the cost of lamp replacement.
An air conditioner unit according to the present invention includes an optical fiber group 17 formed by bundling a plurality of optical fibers 16 emitting a part of propagating light from side faces thereof; an air duct 10 that incorporates the optical fiber group 17 in a space 13 through which air passes; and a light source 30 that supplies ultraviolet light to each of the optical fibers 16. Since the intensity of the light is inversely proportional to the square of the distance from the light source, if the same sterilization effect is to be obtained, the irradiation intensity of the ultraviolet light can be reduced when the irradiation distance is shorter. In other words, in this air conditioner unit, since the plurality of optical fibers 16 are arranged in the air duct 10, the air (air flow) in the air duct 10 can be sterilized by the ultraviolet light of the LED having a small output from the light source 30.